We're talking operating system classification - with PAE all the other 32-bit limitations still exist. Why are you mentioning 4GB+ per process? It's just a way of increasing address space, being able to ustilise 4GB+ total RAM within the other 32-bit limitations and nothing more.
Linux seems to cope quite nicely - you can boot exactly the same 32-bit system with or without a PAE kernel & it will run without changing anything else. No special skills needed. The fact that MS enabled it on 32-bit server editions says it's their choice not to do so on other editions.